BRAMPTON, Ont. - A man accused of killing his ex-girlfriend, carving up her body and scattering her remains in the Toronto area did "terrible and appalling things" to cover up the gruesome slaying, but that doesn't make him a murderer, his lawyer argued Tuesday.

Chun Qi Jiang admitted on the stand to disposing of 41-year-old Guang Hua Liu's remains, destroying evidence and lying to police, but said it was his mother who killed and dismembered his on-again, off-again girlfriend.

"As despicable as those things are, they do not make him a killer," defence lawyer Kathryn Wells said in her closing arguments.

Jiang's actions, while horrific, were nothing more than a "desperate attempt to cover up the crime in order to protect his mother," Wells said, adding that his mother has since died.

"She is now gone from this world and he doesn't need to protect her anymore," she said.

Liu's body parts were found in parks and waterways across the Greater Toronto Area in August 2012, triggering a massive investigation. Jiang was arrested that same month.

He was originally charged with second-degree murder but the charge was upgraded to first-degree murder last summer.

Prosecutors have alleged Jiang was unhappy with Liu for reconciling with a new boyfriend. They allege Jiang killed Liu in his home before cutting up her body and disposing of her remains.

In his last pitch to the jury Tuesday, Crown attorney Brian McGuire painted Jiang as a "calculating liar" who showed signs of "obsessive jealousy" towards Liu and would do anything to get away with her murder.

It's "no coincidence" Liu was killed the same day she told a friend she was getting back together with her new boyfriend, he told the court.

"Ms. Liu had made her decision," he said. "But it wasn't one Mr. Jiang wanted to hear."

The defence told jurors not to fall for the "jealous lover" narrative, saying the evidence could just as easily point to Jiang's mother. The mother's death wasn't considered suspicious.